Revetment block mat using toe blocks with linear sides

ABSTRACT

A mat of revetment blocks formed with interior revetment blocks having interlocking arms and sockets. The mat has opposing sides formed with revetment toe blocks having either an arm or socket that interlocks with a socket or arm of the interior revetment blocks. The toe blocks each have an outer linear edge that forms a linear border of the mat. The toe blocks rest on respective anchor portions that extend into the ground. The mat can be used to form a roadway.

RELATED APPLICATION

This new non-provisional patent application is a divisional patentapplication of pending U.S. non-provisional application Ser. No.14/934,359 filed Nov. 6, 2015, which claims the benefit of provisionalapplication 62/123,095, filed Nov. 6, 2014.

TECHNICAL FIELD OF THE INVENTION

The present invention relates in general to revetment blocks forcontrolling erosion, and more particularly to a mat of interlockingrevetment blocks in which the perimeter thereof is linear and does nothave either interlocking arms or sockets around the border.

BACKGROUND OF THE INVENTION

Erosion control blocks protect the underlying ground against erosion ofthe soil and maintain the terrain in a desired condition. Interlockingerosion control blocks are well adapted for protecting the ground, assuch type of blocks are constructed with interlocking arms that extendfrom one or more sides of a block, and interlocking sockets formed inother sides of the block. When interlocked together, neighbor blockscannot be laterally moved from each other, thereby allowing high waterflows thereover without compromising the integrity of a mat of blocks.

An interlocking revetment block generally has at least four sides withat least one interlocking arm or an interlocking socket on each side.Often, the corners of the revetment block are formed at an angle so thatoverall the block has an octagonal shape. Such a revetment block isdisclosed in U.S. Pat. No. 5,556,228 by Smith. As can be appreciated, ifa mat of such type of revetment blocks were installed, then theperimeter or border would have exposed interlocking arms and unfilledinterlocking sockets. The irregular edge of the block with unused armsor sockets allows the border blocks to more easily break or allow cracksto form through the block.

Interlocking revetment blocks are also formed with one or more verticalholes formed therein, from the top surface to the bottom surface. Thevertical holes allow vegetation to grow therein and help anchor theblock to the ground. A revetment block that has five vegetation holestherein is disclosed in U.S. Pat. No. 8,123,435, also by Smith.

Revetment blocks are often installed in watershed areas where soilerosion is to be prevented. The watershed areas are in many instanceslocated in areas controlled by local or federal governments, and theprimary concern is the long term protection of such areas from theerosion of soil due to frequent high-volume flows of rainwater, and thelike. Generally, the aesthetics of such an area is not a concern, as theprevention of erosion is the primary goal to be achieved.

Generally, large areas of revetment blocks are installed using a singletype or style of block. The use of two different types of blocks isusually not an alternative that is available because two different typesof blocks must be maintained either in inventory, or must be fabricatedfor the project. For example, if an area to be protected from erosionrequires the borders to be linear and without unused interlocking armsor sockets, then different shaped blocks must be employed. Thefabrication of different style interlocking blocks necessitates the useof different shape molds at the fabrication plant. Revetment blocks aretypically fabricated with heavy duty steel molds that are repeatedlyused, thus making such molds expensive. Moreover, if a different stylerevetment block is to be fabricated, this requires that the entirefemale mold and male press head be removed and replaced with a differentmold and press head adapted for fabricating the different shape block.This results in more costly revetment block products.

From the foregoing, it can be seen that a need exists for a mat ofinterlocking revetment blocks where the perimeter thereof is linear anddevoid of interlocking arms or sockets. Another need exists for a mat ofinterlocking revetment blocks that has a linear perimeter so that iteasily abuts against a linear border of concrete, such as a paved road,sidewalk, etc. Yet another need exists for a mat of interlockingrevetment blocks that has a linear border, so that such mat can be usedas a roadway and the perimeter is less likely to deteriorate and morelikely to remain intact, even with heavy equipment traffic running overthe edges of the mat. A further need exists for an economical method offabricating different style revetment blocks using a universal moldwhere various components can be fastened or removed from the male andfemale mold parts, without changing out the entire mold.

SUMMARY OF THE INVENTION

In accordance with the principles and concepts of the invention,disclosed are different style revetment blocks that can be installed andinterlocked so that there is a linear border around at least a portionof the area covered by such blocks. In a preferred embodiment, in whichthe perimeter of the area to be covered is linear, the revetment blocksinclude border blocks with a linear side, corner blocks with two linearsides, and interior blocks that interlock with each other as well as theborder and corner blocks.

A feature of the invention is that a mat of the revetment blocks can beinstalled in abutment with a concrete curb or other linear edge, so thatthere is no unused interlocking arms or sockets on the desired bordersof the perimeter of the area to be covered. With this arrangement, thereis less chance that the border blocks will break or crack when subjectedto heavy loads. Otherwise, the unused arms or sockets that are notinterlocked with other blocks could crack or break and degrade theintegrity of the mat.

An additional feature of the invention is that the revetment blocks areconstructed with positive interlocking arms and sockets so that theblocks cannot be separated from each other by substantial lateralmovement. The positive interlocking aspect allows the blocks to beindividually removed only by upward lifting of a block. A mat of suchrevetment blocks can thus withstand substantial hydraulic forces ofwater flowing thereover without compromising the stability of the mat ofblocks.

A universal mold can be employed to efficiently and economicallyfabricate the different types of revetment blocks required to constructa mat of blocks having a linear border. The mold includes a female moldbody and a male press head, each with arm and socket components that canbe attached or removed to reconfigure the mold to fabricate thedifferent types of revetment blocks. The mold body and press head can beeasily modified with the arm and socket components so that the entiremold parts do not have to be replaced, thereby allowing multiple typesof revetment blocks to be fabricated by a single reconfigurable mold,without having to have entirely different molds, which would beexpensive.

According to an embodiment of the invention, disclosed are revetmentblocks for making a mat having a linear border. An interior block hastwo engaging arms and two engaging sockets, the arms for engaging withrespective sockets of two neighbor revetment blocks, and the sockets forengaging with respective arms of two other neighbor blocks. A borderblock has three engaging members for interlocking with respectivemembers of three neighbor revetment blocks. The border block has alinear edge forming a portion of the border of the mat. A corner borderblock has two engaging members for engaging with the respective membersof two border blocks. The corner block has two linear sides.

According to another embodiment of the invention, disclosed arerevetment blocks for making a mat having a linear border. The matincludes a plurality of interior revetment blocks, each having twoengaging arms and two engaging sockets for engaging with respectiveneighbor revetment blocks. A first revetment toe block has a socket forengaging with an arm of one of the interior blocks, where the first toeblock has a linear edge without an arm or a socket on a side oppositethe socket of the first toe block. A second revetment toe block has anarm for engaging with a socket of one of the interior blocks, where thesecond toe block has a linear edge without an arm or a socket on a sideopposite the arm of the second toe block. The first toe block and thesecond toe block are adapted for laying on a ground surface to beprotected from erosion. Each of the first and second toe blocks has arespective anchor portion that is rectangular in shape and extendsorthogonal to and downwardly from the first and second toe blocks. Theanchor portion of each of the first and second toe blocks is adapted forbeing buried in the ground.

According to yet another embodiment, disclosed are revetment blocks formaking a mat having a linear border. The mat includes a plurality ofinterior revetment blocks, each having two positive interlocking armsand two positive interlocking sockets for engaging with respectiveneighbor revetment blocks. A first revetment toe block has a positiveinterlocking socket for engaging with an interlocking arm of one of theinterior blocks. The first toe block also has a linear edge without anarm or a socket on a side opposite the interlocking socket of the firsttoe block. A second revetment toe block has a positive interlocking armfor engaging with an interlocking socket of one of the interior blocks.The second toe block has a linear edge without an arm or a socket on aside opposite the interlocking arm of the second toe block. The firsttoe block and the second toe block are adapted for laying on a groundsurface to be protected from erosion. Each of the first and second toeblocks has a respective anchor portion that is rectangular in shape andextends orthogonal to and downwardly from the first and second toeblocks. The anchor portion of each of the first and second toe blocks isadapted for being buried in the ground.

With regard to a further embodiment of the invention, disclosed is amethod of forming a roadway using revetment blocks. The method includesdigging spaced-apart trenches in a path of the roadway; installinginterior revetment blocks along the path of the roadway between thespaced-apart trenches, where the interior revetment blocks have arms andsockets. The method further includes using revetment toe blocks onopposing sides of the interior revetment blocks, where each toe blockincludes at least on arm or one socket, and where each revetment toeblock is associated with an anchor portion; and installing the anchorblock portions of the toe blocks in the spaced-apart trenches, andengaging the arm or socket of the respective toe blocks with therespective socket or arm of the neighbor interior revetment blocks.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages will become apparent from the followingand more particular description of the preferred and other embodimentsof the invention, as illustrated in the accompanying drawings in whichlike reference numbers generally refer to the same parts, functions orelements throughout the views, and in which:

FIG. 1 is a mat of twelve interlocking revetment blocks having a linearborder all around the perimeter of the mat;

FIG. 2 is an exploded view of various components of a block plantfabrication unit;

FIG. 3 is an isometric view of a universal mold box adapted forfabricating different shape revetment blocks;

FIG. 4 is an isometric view of a universal press head for use with theuniversal mold box of FIG. 3;

FIG. 5 is a top view of a mat of revetment blocks having interiorrevetment blocks and opposing edge revetment blocks having respectivelinear edges;

FIG. 6 is a cross-sectional view of the mat of revetment blocks takenalong line 6-6 of FIG. 5; and

FIG. 7 is an isometric view of an edge revetment block having aninterlocking part and an anchor part.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a small twelve-block mat 13 of interlocking revetmentblocks. The mat 13 includes a number of different shape blocks in orderto achieve a linear perimeter, shown by broken line 15. Although theperimeter 15 is generally linear, it has small indentions 14 where thediagonal corner of neighbor blocks meet. Accordingly, as used herein theterm linear generally means that there are two or more blocksinterlocked together with no arms or sockets on the selected edges orborders of such interlocked blocks, and the borders can be curved basedon the articulation ability of the blocks. The mat 13 also includesdiagonal angled corners 16. However, the mat 13 does not include anyarms or sockets along the perimeter, as each border block is constructedwith one or two linear sides that do not have either an arm or a socket.This prevents the breakage of the border blocks when heavy loads arecarried on the unused arms and sockets of the border blocks. Forexample, the first corner block 1 is a border block and is constructedwith a first side 18 and a second side 20 orthogonal thereto, andneither side has an arm or a socket. Rather, such sides are linear.Opposite linear side 18 of the first corner block 1 is an interlockingsocket 22, and opposite linear side 20 of the first corner block 1 is aninterlocking arm 24. The border of the area to be covered may extend allaround the perimeter, but the border may also encompass only one side,two or three sides of the perimeter.

The top edge of border block 2 is constructed with a single linear side26 that is collinear with the linear side 18 of the first corner block1. Opposite the linear side 26 of border block 2 is an interlockingsocket 28. The border block 2 has a side with a socket 30 thatinterlocks with the arm 24 of the first corner block 1. Opposite thesocket 30 of border block 2 is an interlocking arm 32.

The second corner block 3 is also a border block and is constructeddifferently from first corner block 1 and border block 2. The secondcorner block 3 is constructed with a first linear side 34, and a secondlinear side 36 that is orthogonal to the first linear side 34. Thesecond corner block 3 is constructed with an interlocking socket 38opposite linear side 36, and an interlocking socket 40 opposite linearside 34. The socket 38 interlocks with arm 32 of the neighbor borderblock 2.

The side border block 4 is constructed with a single linear side 42 andan interlocking arm 44 opposite the linear side 42. An interlocking arm46 is constructed on a side of side border block 4, where the arm 46interlocks with a socket 22 of the first corner block 1. Side borderblock 4 is constructed with an interlocking socket 48 opposite theinterlocking arm 46.

A interior block 5 is one of many interior blocks of a typical mat, andincludes an arm or a socket on each side thereof. In particular,interior block 5 includes an interlocking socket 50 that interlocks withthe arm 44 of the side border block 4. Interior block 5 includes aninterlocking arm 52 formed on a side that is opposite the interlockingsocket 50. An interlocking arm 54 is formed on interior block 5 andinterlocks with the socket 28 of border block 2. An interlocking socket56 is formed in block 5 opposite interlocking arm 54. The interior block5 is constructed differently from border blocks 1-4. Except for thearrangement of vegetation holes formed in interior block 5, theinterlocking arms and sockets of interior block 5 are constructed verysimilar to the revetment block disclosed in U.S. Pat. No. 5,556,228.

Side border block 6 is constructed with a linear side 58 that iscollinear with the linear side 36 of the second corner block 3. The sideborder block 6 is constructed with an interlocking socket 60 oppositethe linear side 58, where the interlocking socket 60 interlocks with theinterlocking arm 52 of interior block 5. An interlocking arm 62 isformed on side border block 6 and is interlocked with the socket 40 ofthe second corner block 3. An interlocking socket 64 is formed in sideborder block 6 opposite the interlocking arm 62.

Side border block 7 is constructed in an identical manner to side borderblock 4, with a linear side 66 and an interlocking arm 68 extending froma side opposite the linear side 66. The linear side 66 of side borderblock 7 is collinear with the linear side 42 of side border block 4. Theside border block 7 has an interlocking arm 70 that interlocks with theinterlocking socket 48 of the side border block 4. An interlockingsocket 72 is formed opposite the interlocking arm 70.

Interior block 8 is constructed identical to the interior lock 5.Interior block 8 has an interlocking socket 74 that interlocks with theinterlocking arm 68 of side border block 7. An interlocking arm 76 isformed opposite the interlocking socket 74. An interlocking arm 78 ofinterior block 8 interlocks with interlocking socket 56 of interiorblock 5, and an interlocking socket 80 is formed in interior block 8opposite interlocking arm 78.

Side border block 9 is constructed in an identical manner as side borderblock 6. Side border block 9 includes a linear side 80 that is collinearwith the linear side 58 of side border block 6. Side border block 9 isconstructed with an interlocking socket 82 that is opposite the linearside 80, and interlocking socket 82 interlocks with interlocking arm 76of interior block 8. An interlocking arm 84 is interlocked with theinterlocking socket 64 of side border block 6. An interlocking socket 86is formed in side of border block 9 opposite the interlocking arm 84.

The third corner block 10 is a border block and is constructed with afirst linear side 88 and a second linear side 90 orthogonal thereto,where neither side has an arm or a socket. Linear side 88 is collinearwith side 66 of side border block 7. Opposite linear side 88 of cornerblock 10 is an interlocking arm 94, and opposite linear side 90 ofcorner block 10 is an interlocking arm 92 that is interlocked with thesocket 72 of side border block 7.

The bottom border block 11 is constructed with a linear side 96 that iscollinear with the linear side 90 of the third corner block 10. Thebottom border block 11 includes an interlocking arm 100 opposite theinterlocking socket 98, and includes an interlocking arm 102 oppositethe linear side 96. The interlocking socket 98 interlocks withinterlocking arm 94 of the third corner block 10.

Lastly, in the twelve-block mat 13, there is a fourth corner block 12that is a border block and is constructed with a first linear side 104that is orthogonal to a second linear side 106. The linear side 104 iscollinear with the linear side 96 of bottom border block 11. Similarly,the linear side 106 of the fourth corner block 12 is collinear with thelinear side 80 of side border block 9. An interlocking socket 108 isformed in the fourth corner block 12 opposite the linear side 106, andan interlocking arm 110 is formed in the fourth corner block 12 oppositethe linear side 104. The interlocking socket 108 interlocks with theinterlocking arm 100 of the bottom border block 11. The interlocking arm110 of the fourth corner block 12 interlocks with interlocking socket 86of side border block 9.

While the mat 13 includes only twelve interlocking blocks, in practicemany more interlocking blocks would be employed to cover a large groundarea. A larger mat of interlocking blocks, where the mat has a linearborder or perimeter, can be installed by adding additional blocks 4 or 7in the first column to make the mat as long as desired. The additionalside border blocks 4 or 7 would be added in the first column at line112. In order to make the mat 13 longer, additional interior blocks 5 or8 would be added in the second column at line 112. The additionalinterior blocks 5 or 8 would have interlocking sockets that interlockwith the respective interlocking arms of the added side border blocks 4or 7. Lastly, in order to lengthen the mat 13, additional side boarderblocks 6 or 9 would be added at line 112 in the third column of the mat13. The added side border blocks 6 or 9 would have interlocking socketsthat interlock with the respective interlocking arms of the addedinterior blocks 5 or 8.

Of course, when making a mat of interlocking revetment blocks longerthan the mat 13, one would start at the bottom or top of the mat andinstall as many blocks as necessary until the other end of the mat isreached. The mat 13 can be made wider than the three-block wide mat 13by adding additional top border blocks 2 at line 114, between cornerborder blocks 1 and 3. Similarly, the mat 13 can be made wider by addingadditional interior blocks 5 between side border blocks 4 and 6, at line114. The same can take place by adding additional interior blocks 8between side border blocks 7 and 9 at line 114. A wider mat 13 isachieved by adding additional bottom border blocks 11 between the thirdand fourth corner blocks 10 and 12, at line 114.

Although the interlocking blocks of the mat 13 can be constructed indifferent sizes, a preferred embodiment of each of the interlockingblocks has a length/width dimension of 15 inches by 15 inches. Theinterlocking blocks can be 4.5 inches thick and fabricated with 4,000psi concrete. A mat of interlocking blocks for making a roadway ten footwide would be installed with eight blocks across. A roadway fifteen feetwide would be installed with twelve blocks across. A mat 13 of revetmentblocks can be installed in abutment with a roadway concrete curb orstrip 27 or 29, or other linear edge, so that there is no unusedinterlocking arms or sockets on the desired borders of the perimeter ofthe area to be covered.+

As noted above, each interlocking block of a mat 13 is constructed withvegetation holes therein. In a preferred embodiment, each block isformed with five vegetation holes, in the location of the five dots of agambling dice. The vegetation holes, one shown as numeral 113 in thefirst corner block 1, are formed in the manner described in U.S. Pat.No. 8,123,435, the disclosure of which is incorporated herein byreference. In general, the vegetation holes are formed as a verticalcone shape, with the larger opening in the bottom of the block. Thelarger opening in the vegetation holes placed in the bottom of eachinterlocking block allows the blocks to be better anchored to the groundwhen the holes are filled with soil, small stones, vegetation, etc.Thus, the interlocking blocks should not be turned upside down andinstalled.

If those skilled in the art prefer to make the vegetation holes ascylinders with the same size opening in the top and bottom of theblocks, then the blocks can be installed right side up or upside down.If this is desired, then the first corner block 1 can be turned upsidedown, reoriented and installed in the position of the fourth cornerblock 12. Similarly, the top border block 2 can be turned upside down,reoriented and installed in the position of side border blocks 6 and 9.Lastly, the side border block 4 can be turned upside down, reorientedand installed in the position of bottom border block 11.

In the linear-border mat 13 of FIG. 1, there are nine different types ofinterlocking blocks. In the conventional construction of such blocks, ina dry cast block plant process, there would be required nine differentmolds for making each type of block. This is expensive, as moldsconstructed of steel for making revetment blocks, are expensive. Thecost of a typical mold for block plant fabrication of revetment blockscan range upwardly of $35 k-$40 k.

FIG. 2 illustrates in rudimentary form the equipment for mass producingrevetment blocks using dry cast molds and block plant techniques. Theresulting revetment block fabricated is shown as interior block 5 in itscompleted form after the casting process. According to this technique, amold box 120 is used, which has a depression with an outer perimeter inthe shape of the block to be formed therein, except for the vegetationholes. It can be seen that this mold box 120 is for making the interiorblock 5 of FIG. 1. The depth of the depression 122 in the mold box 120is about twice the actual thickness of the interior block 5. The moldbox 120 has hollow outwardly-directed depressions 124 and 126 to formthe respective interlocking arms 52 and 54 of the interior block 5. Twoinwardly-directed arms 128 and 130 in other sidewalls of the depression122 of the mold box 120 form the two corresponding sockets 50 and 56 inthe interior block 5. The mold box 120 is constructed of solid steel andcan be used many times to make revetment blocks without replacement orrepair due to wear. A small draft angle is formed in the sidewalls ofthe depression 122 of the mold box 120 to allow the interior revetmentblock 5 to remain on a metal pallet 140 when the mold box 120 is lifted.

The block plant equipment further includes a reciprocating unit 130which includes a plunger 132 and a thick square plate 134 (shown inbroken lines) attached to the bottom thereof. The plate 134 can be aboutthe size as the top of the mold box 120. A press head 136 is attached tothe bottom of the plate 134. The press head 136 is shaped in the outlineof the interior block to be formed, and fits down into the top portionof the hollowed out part 122 of mold box 120. As can be appreciated,when making a different shaped revetment block, a different mold box 120and a corresponding different press head 136 are required. As notedabove, the molding apparatus for a different mold box and press head canrange upwardly to $35,000 to $40,000.

A further component 150 of the mold box 120 is a set of solid core cans152 that form the vegetation holes in the interior revetment block 5.This apparatus 150 is shown to the side of the mold box 120, but inpractice is welded to the bottom of the mold box 120. The interior block5 is formed with five vegetation holes, and thus the array of vegetationholes 150 also includes five solid core cans 152. The bottom of eachsolid core can 152 is attached to a support rod 154 (shown in brokenline), and the ends of the support rods 154 are welded to the bottom ofthe mold box 120. While not shown, the press head 136 is constructedwith five cylindrical voids in the bottom thereof to receive therein thecore cans 152.

A further component of the block plant system is a movable pallet 140that underlies the mold box 120. The pallet 140 is a thick steel platethat is laterally moved under the mold box 120 to temporarily form thebottom of the mold box 120. After the interior block 5 is cast in themold box 120, the mold box 120 is lifted and the molded interior block 5remains on the pallet 140. The pallet 140 is situated on a conveyor-likeapparatus so that it can be moved away from the mold box 120 anddownline to allow the interior revetment block 5 to be cured. At thesame time, another pallet is moved under the mold box 120, whereupon themold box 120 is lowered onto the empty pallet 140 and the block castingprocess is repeated.

In practice, the mold box 120 resting on the pallet 140 is filled withconcrete of the desired psi, and with a predetermined amount. In the drycast technique, the concrete partially filling the mold box 120 has onlyabout 7% water and thus is not runny. Then, the press head 136 is pusheddown into the mold box 120 to compress the concrete mix filling thebottom portion of the mold box 120. Additionally, the press head 136 isvibrated to remove all air pockets to assure the integrity and strengthof the resulting interior block 5. When the plate 134 above the presshead 136 contacts the top of the mold box 120, this is sensed by asensor (not shown), whereupon the plunger 132 is moved upwardly,bringing with it the plate 134 and the press head 136 attached thereto.Also lifted by means not shown is the mold box 120 so that it is liftedfrom the pallet 140. The mold box 120 is lifted and separated from themolded interior block 5 which remains on the pallet 140. As noted above,the pallet 140 with the newly-molded interior block 5 resting thereon ismoved downline. The procedure is repeated to fabricate another block ofthe same shape, by lowering the mold box 120 onto a subsequent pallet,partially filling the mold box 120 with fresh concrete, and repeatingthe process described above.

As illustrated above, there are a number of different revetment blocksneeded to provide a linear border around the mat 13 of revetment blocks.A corresponding number of different molds would be required in order tofabricate nine different shaped revetment blocks for the mat 13. Thiswould be prohibitively expensive. In accordance with a feature of theinvention, a single mold with replaceable arm/socket members can beutilized to thereby make a universal mold adapted for makingdifferent-shaped blocks by attaching or removing the arm/socket membersto the body of the mold.

With regard to FIG. 3, there is disclosed a universal mold 160 and theassociated components. In particular, the universal mold 160 includes abody 162 having a hollowed out part 164 formed in the basic shape of theperimeter of the block to be formed, including the four angled corners,one shown as numeral 169. The body 162 of the universal mold 160includes the two outwardly-directed depressions 166 and 168 that wouldform the corresponding arms 52 and 54 of the interior block 5. As willbe described in detail below, the outwardly-directed depressions 166 and168 can be filled in with respective filler plugs to effectively makethe universal mold 160 function to eliminate one or the other of theinterlocking arms 52 or 54. Rather than forming the inwardly-directedarms that would otherwise form the sockets 50 and 56 in the interiorrevetment block 5, the two sides of the depression 164 formed in themold body 162 are made planar. The planar sides 170 and 172 correspondto the respective planar sides of the border blocks of the mat 13.

The body 162 of the universal mold 160 is constructed to make any of thefour sides (excluding the angled corners) planar and without any arm orsocket. This is accomplished by making the socket sides 170 and 172 ofthe mold body 162 planar, as described above. When it is desired to forma socket in either of the two sides 170 and 172, then a socket member174 is bolted in the position where a socket should be formed in therevetment block. The socket member 174 is shown removed and above themold body 162 for purposes of clarity. The socket member 174 is formedof steel and has two threaded holes 176 therein. Bolts 178 pass throughrespective holes 180 formed in the body 162 of the universal mold 160and are fastened into the threaded holes 176 of the socket member 174.This removably fastens the socket member 174 to the inside surface 170of the mold body 162. With this arrangement, this side 170 of the moldbody 162 can be modified to be either a planar side when the socketmember 174 is removed, or a socket when the socket member 174 is boltedto the mold body side 170. The socket member 182 is shown bolted inposition to the mold body side 172. In like manner, when the socketmember 182 is removed, the side 172 of the mold body depression 164 isplanar.

The mold body 162 includes an outwardly-extending depression 166 thatotherwise forms an arm 52 of the revetment block to be formed. An armmember 184 has a shape substantially like that of theoutwardly-extending depression 166, but has a planar side 186. When thearm member 184 is inserted into the depression 166, it fills thedepression 166 and provides an inside planar side 186 that is coplanarwith the sidewall of the depression 164 of the mold body 162. The otheroutwardly-extending depression 168 of the mold body 162 is shown with anarm member 188 inserted therein, and the planar side 190 of the armmember 188 is coplanar with the respective side of the mold body 162.The arm member 184 is fastened within the outwardly-extending depression166 using bolts 192 inserted through respective holes in the mold body162 and threaded into threaded holes (not shown) in the arm member 184.

As can be seen, the mold body 162 is formed so that two sides 170 and172 are normally planar and can be made into corresponding sockets bybolting respective socket members 174 and 182 thereto. Conversely, theother two sides of the mold body 162 are formed so that such sides areconstructed with normally outwardly-extending depressions 166 and 168for forming corresponding arms of the revetment block, but have armmembers 184 and 188 inserted therein to make the respective mold bodysides planar.

The press head 200 shown in FIG. 4 (without the overlying plate 134) canalso be constructed so as to be universal in making the different shapesof revetment blocks. The press head 200 can function in conjunction withthe universal mold 160. The press head 200 includes a body 202 that isthe same general shape of the block to be made so that it presses downon the wet concrete in the mold body 162 to compress the wet concrete ofthe block. The press head body 202 can thus be constructed in the sameshape as the hollowed out part 164 formed in the mold box 162, havingtwo sockets 204 and 206, and two planar sides 208 and 210. Socketmembers 212 and 214 are insertable into the respective sockets 204 and206 and bolted thereto by bolts 216. Corresponding arm members 218 and220 are boltable to the planar sides 208 and 210. The insertable socketmembers 212 and 214 as well as the arm members 218 and 220 are used tomodify the outline shape of the press head body 202 for correspondenceto the manner in which the mold box 162 is modified. In other words,when there is no arm member 184 inserted into the outwardly-directeddepression 166 of the mold body 162, then there would be an arm member218 bolted to the corresponding position in the press head body 202.Thus, when the outwardly-extending depression 166 in the mold body 162is vacant and filled with concrete, the corresponding arm member 218attached to the press head body 202 would come down and compress theconcrete that partially fills the outwardly-extending depression 166 inthe mold body 162 and form an arm. The same would be true with the useor nonuse of the arm member 220 attachable to the press head body 202 inthe position corresponding to the removable arm member 188 of the moldbody 162.

A socket member 212 shaped much like socket member 174 can be fastenedto the press head body 202 in the location corresponding to mold bodyside 170. The socket member 174 is slightly larger than the arm member184 of the mold body 162 to make a block that allows a desired degree ofarticulation between mating arms and sockets of neighboring revetmentblocks. If the socket member 174 is bolted to the side 170 of the moldbody 162, then the similar-shaped socket member 212 would not be boltedinto the socket 204 of the corresponding side of the press head body202. On the other hand, if the socket member 174 was not bolted to theside 170 of the mold body 162 to form a planar surface, then the socketmember 212 would be bolted into the corresponding socket 204 of thepress head body 202. The same would be the case when the socket member214 is used or not used on the side of the press head body 202corresponding to the side of the mold body 172 to which the socketmember 182 is shown attached. With this socket member arrangement, whena planar side 170 of the mold body 162 has no socket member attachedthereto, the press head body 202 does, whereby the wet concrete adjacentthe planar side 170 of the mold body 162 will be compactedappropriately.

When fabricating the interior blocks 5 and 8 of FIG. 1, the moldingapparatus would be modified according to the following. Since theinterior block 5 has two arms and two sockets, then the arm members 184and 188 would be removed from the corresponding outwardly-extendingdepressions 166 and 168 of the mold box 162, and both arm members 218and 220 would be bolted to the respective planar sides 208 and 210 ofthe press head 202. The two arm members 218 and 220 of the press head200 would thus come down into the mold box body 162 and into thecorresponding sockets 166 and 168 to compress the concrete arm members52 and 54 of the block 5. Outwardly-extending arms 52 and 54 would thusbe formed on the interior block 5. When forming the two sockets 50 and60 of the interior block 5, the two socket members 174 and 182 would bebolted to the respective planar sides 170 and 172 of the mold body 162.The press head 202 would be configured so that both arm members 212 and214 would be removed from the respective sockets 204 and 206. Thesockets 50 and 60 of the interior block 5 would thus be formed.

In forming, for example, the border block 9 which has an arm 84, twosockets 82 and 86 and a linear side 80, the universal mold 160 would beconfigured as follows. The arm member 188 would not be bolted into thedepression 168 of the mold body 162 so that the arm 84 of the borderblock 9 would be formed. The arm member 220 would be bolted to the presshead body 202 to compress the concrete in the socket 168 of the moldbody 162. The arm member 184 would be bolted in the outwardly-extendingdepression 166 of the mold body 162 and the arm member 218 of the presshead body 202 would be removed so that a corresponding arm would not beformed in the border block 9. The linear side 80 of the border block 9would thus be formed instead of an arm. Since the border block 9 has twosockets 82 and 86, both socket members 174 and 182 would be bolted tothe respective sides 170 and 172 of the mold body 162, thereby causingtwo sockets 82 and 86 to be formed in the border block 9. The press headbody 202 would be modified so that the arm members 212 and 214 would beremoved to receive therein the respective arm members 174 and 182 of themold body 162. The border block 9 would thus be formed by the universalmold 160.

From the foregoing, a universal mold 160 is disclosed so that it can beused to fabricate different shape interlocking revetment blocks usingthe same general mold body, by attaching or removing various socket orarm members therefrom. The foregoing has been described in connectionwith a preferred embodiment in which interlocking revetment blocks areconstructed and installed in a mat. Those skilled in the art may applythe teachings disclosed herein to construct revetment blocks and othertypes of blocks with arms and sockets that interengage, but do notpositively interlock to prevent lateral separation.

FIGS. 5-7 illustrate another embodiment of a mat 230 of revetmentblocks, where the blocks are installed within a border of spaced-aparttoe blocks 234 and 238. The interior revetment blocks, one shown as 232,are constructed with two interlocking arms and two interlocking sockets,much like the interior blocks 5 described above. The interlockinginterior revetment blocks 232 provide an excellent roadway adjacent toan area where water can occasionally flow and provide the possibility oferosion. According this embodiment, the mat 230 of interior blocks 232has a first border constructed of toe blocks 234, each of which has aninterlocking socket 236 formed therein. A second and oppositely-locatedborder is constructed of toe blocks 238, each of which has aninterlocking arm 240.

The respective sockets 236 the first border of toe blocks 234 interlockwith the corresponding arms of the interior blocks 232. The linear outerside 237 of the toe blocks 234 forms a straight or linear edge to theroad. In like manner, the socket of each interior block 232 forming theopposite side of the road, interlocks with a corresponding arm 240 of aneighbor toe block 238. Each toe block 234 is constructed with onesocket 236 and three linear sides, one of which is the outer side 237 ofthe toe block 234. Each toe block 238 is similarly constructed with onearm 240 and three linear sides, one of which is the outer side 239 ofthe toe block 238. With this arrangement of toe blocks 234 and 238, eachside of the mat 230 of interior blocks 232 is constrained within thelateral area between the respective rows of toe blocks.

The details of the construction of the toe block 234 is illustrated inFIGS. 6 and 7. The purpose of the toe blocks 234 and 238 is to anchorthe sides of the mat 230 in the ground and prevent the erosion of soilby water attempting to flow under either side of the mat 230. The toeblock 234 is constructed with two parts. Atop interlocking part 242 ofthe toe block 234 has the interlocking socket 236 and is substantiallythe same size and thickness as the neighbor interior block 232. Inpractice, the socket 236 of the toe block 234 is somewhat larger thanthe arm of the interior block 232 to allow a desired degree ofarticulation between the neighbor blocks. An anchor part 244 of the toeblock 234 has a length substantially the same as the interlocking part242, but is narrower in width. The length is measured into the drawing,and the width is measured sideways in the drawing of FIG. 6, and thedepth of the anchor part 244 is measured up and down in the drawing ofFIG. 6. For clarity, these dimensions are set forth in FIG. 7 also. Theanchor part 244 of the toe block 234 is buried in the ground, andpreferably in a trench 245 formed along the side of the road to be pavedwith the mat 230. The depth of the anchor part 244 of the toe block 234can be about 13.5 inches to thereby substantially reduce the possibilityof water eroding under the mat 230 and compromising the integrity andstability thereof. The other toe block 238 is constructed in asubstantially similar manner, except with an interlocking arm 240,rather than an interlocking socket 236.

The row of toe blocks 234 remain adjacent each other due to theinterlocking connection between the neighbor interior blocks 132.However, those skilled in the art may find it advantageous in someapplications to provide the capability for each toe block 234 in the rowto interlock with each other using respective sockets and arms. The samecould be with the other row of toe blocks 238. Also, each toe block 234and 238 is constructed with interior beveled corners, but this is not anecessity to the proper function of the toe blocks 234 and 238. Thebeveled corners of the toe blocks 234 and 238 provide an opening at thecorner intersection between blocks to facilitate the growth ofvegetation and anchoring of the blocks and the mat 230 to the underlyingground.

With reference to FIG. 7, there is illustrated the interlocking part 242of the toe block 234, as well as the anchor part 244. In practice, thetoe block 234 is constructed in two parts by block plant techniques,using respective molds. Three different molds can be utilized, one formolding the interlocking socket part 242 of the toe block 234, a secondmold for making the interlocking arm part 240 of the other toe block238, and a third mold for making the anchor part 244 of both toe blocks234 and 238. As noted above, the interior revetment blocks are about 15inches by 15 inches and 4.5 inches thick (depth). The interlocking part242 of the toe block 234 is made compatible with the interior blocks 232by constructing the interlocking part 242 about fifteen inches wide,about twelve inches long and about 4.5 inches thick (depth). The anchorpart 244 of the toe block 234 is constructed about 4.5 inches wide,about twelve inches long and about 13.5 inches in depth. Those skilledin the art may find that the interior blocks 232 and the toe blocks 234and 238 can be constructed with other dimensions.

When fabricating the toe blocks 234 and 238 using a mold and block planttechniques, it is expected that such block can be made more efficientlyin two parts 242 and 244 and then fixing the two parts together beforebeing installed in an interlocking manner with the interior blocks 232.As such, the interlocking part 242 is first made using the first mold,and then the anchor part 244 is made using a different mold. Then, theinterlocking part 242 is attached to the anchor part 244 by a layer ofmortar 243 therebetween. When the mortar has cured, the interlockingpart 242 is thus fixed to the anchor part 244. The other toe block 238is fabricated in a similar manner. Of course, when a certain mold isfixed to the block plant equipment, many corresponding toe block partswould be molded before changing the mold to make the other toe blockparts.

When constructing a road, such as a conventional ten foot wide road,using a mat of interlocking blocks, the following steps can be carriedout. Two six-inch wide trenches can be formed in each boundary path ofthe road, where the outer edges of the two trenches are ten feet apart.A first lateral row of interior blocks 232 are then installed in aninterlocking manner between the two trenches, and the anchor parts 244of the toe blocks 234 and 238 are then lowered into the respectivetrenches and at the same time interlocked with the respective neighborinterior blocks 232. The space between the anchor parts of toe blocks234 and 238 and the inside of the trenches can be backfilled with dirt.The space between the outside surface of the anchor parts 244 and theouter edge of the trenches can be backfilled with dirt at that time, orat any later time when the road is completed. Subsequent lateral rows ofinterior blocks 232 and toe blocks 234 and 238 are thus installed, withthe second row of interior blocks interlocked with the neighbor interiorblocks. With this technique, a road is provided for carrying the load ofvehicles thereon, the edges are linear and aesthetically pleasing, andthe edges of the road are protected from erosion thereunder by flowingwater during flooding or otherwise.

While the preferred and other embodiments of the invention have beendisclosed with reference to specific revetment blocks, and associatedmethods of construction and installation thereof, it is to be understoodthat many changes in detail may be made as a matter of engineeringchoices without departing from the spirit and scope of the invention, asdefined by the appended claims.

What is claimed is:
 1. A mat made of revetment blocks having a linearborder, comprising: a plurality of interior revetment blocks, eachhaving two engaging arms and two engaging sockets for engaging withrespective neighbor revetment blocks; a first revetment toe block havinga socket for engaging with an arm of one said interior block, said firsttoe block having a linear edge without an arm or a socket on a sideopposite the socket of said first toe block; a second revetment toeblock having an arm for engaging with a socket of one said interiorblock, said second toe block having a linear edge without an arm or asocket on a side opposite the arm of said second toe block; and saidfirst toe block and said second toe block adapted for laying on a groundsurface to be protected from erosion, each said first and second toeblocks having a fixedly attached anchor block that is rectangular inshape and extends orthogonal to and downwardly from the first and secondtoe blocks, the anchor block of each said first and second toe blocksadapted for being buried in the ground.
 2. The mat of revetment blocksof claim 1, wherein said first toe block is attached to a first saidanchor portion with a layer of mortar, and said second toe block isattached to a second said anchor portion with a layer of mortar.
 3. Themat of revetment blocks of claim 2, wherein said first toe block isattached to a first said anchor portion with a layer of mortar beforebeing installed, and said second toe block is attached to a second saidanchor portion with a layer of mortar before being installed.
 4. Aroadway comprised of the mat revetment blocks of claim 1, furtherincluding spaced-apart trenches formed along a path of the roadway, andsaid anchor blocks buried in the respective trenches.
 5. The roadway ofclaim 4, wherein the first and second revetment toe blocks formrespective linear edges of the roadway.
 6. The roadway of claim 5,wherein the linear edges of the revetment toe blocks are formed with amold.
 7. The mat of revetment blocks of claim 1, wherein each revetmenttoe block has a given length that is the same as a length of arespective anchor block attached thereto.
 8. A roadway comprised of themat of revetment blocks of claim 1, wherein the roadway is designed tocarry vehicle traffic.
 9. The roadway of claim 8, wherein said roadwayis anchored to the ground by said anchor blocks.
 10. The roadway ofclaim 8, wherein the arms and sockets of the blocks are articulatedsufficiently so that the roadway can be curved.
 11. A mat made ofrevetment blocks having a linear border, comprising: a plurality ofinterior revetment blocks, each having two positive interlocking armsand two positive interlocking sockets for engaging with respectiveneighbor revetment blocks; a first revetment toe block having a positiveinterlocking socket for engaging with an interlocking arm of one saidinterior block, said first toe block having a linear edge without an armor a socket on a side opposite the interlocking socket of said first toeblock; a second revetment toe block having a positive interlocking armfor engaging with an interlocking socket of one said interior block,said second toe block having a linear edge without an arm or a socket ona side opposite the interlocking arm of said second toe block; and saidfirst toe block and said second toe block adapted for laying on a groundsurface to be protected from erosion, each said first and second toeblocks having a fixedly attached anchor block that is rectangular inshape and extends orthogonal to and downwardly from the first and secondtoe blocks, the anchor block of each said first and second toe blocksadapted for being buried in the ground.
 12. The mat of revetment blocksof claim 11, wherein said anchor portions are attached to the respectivefirst and second toe blocks with a layer of mortar.
 13. A roadwaycomprised of the mat revetment blocks of claim 11, further includingspaced-apart trenches formed along a path of the roadway, and saidanchor blocks buried in the respective trenches.
 14. The roadway ofclaim 13, wherein the first and second revetment toe blocks formrespective linear edges of the roadway.
 15. A method of forming aroadway using revetment blocks, comprising: digging spaced-aparttrenches in a path of the roadway; installing interior revetment blocksalong the path of the roadway between the spaced-apart trenches, wherethe interior revetment blocks each have arms and sockets; usingrevetment toe blocks on opposing sides of the interior revetment blocks,where each toe block includes at least one arm or one socket, and whereeach revetment toe block is associated with an anchor portion; andinstalling the anchor portions of the toe blocks in the spaced-aparttrenches, and engaging the arm or socket of the respective toe blockswith the respective socket or arm of the neighbor interior revetmentblocks.
 16. The method of claim 15, further including using revetmentblocks with positive interlocking arms and sockets for the roadway. 17.The method of claim 15, further including associating the revetment toeblocks with the respective anchor portions by attaching each revetmenttoe block to a respective anchor portion with a layer of mortar.